How can I control the viewport without a mouse?
You won't have fine-tuned control of the viewport without a mouse, but there are extensive options for controlling it via the keyboard:


You can rotate the viewport using 2, 4, 6, and 8. You can also change between "Perspective" and "Orthographic" views by pressing 5.
By holding ctrl and any of the above, you can pan the view.
You can press / to switch between local and global view.
You can use Shift 2 and Shift 6 to roll the view, as of Blender 2.69 (r59707).
You can centre the view on an object by pressing "." on the number pad.
You can zoom in and out of the view using + and -.
You can access the current camera view with 0.



  * Note: All of the number commands require that you either use your numberpad or enable "emulate numpad" in the preferences.